Truck concrete mixer



J. EGGERT TRUCK CONCRETE MIXER Original Filed Dec. 7, 1929 JOEPH EGGERT GEM fiamgd 4V; Gttomeg 5 Patented Mar. 19, 1935 .UNITED STATES TRUCK CONCRETE MIXER. Joseph Egge'rt, Columbus, Ohio, assignmto The corporation of Ohio Jaeger Machine Company, Columbus, Ohio. a

Original application December '1, 1929, Serial No.

412,529. Divided and this appl cation December 21, 1931, Serial No. 582,240 7 8Claima.

This invention relates generally to concrete mixing apparatus and particularly to such as have a mixing drum mounted on a motor vehicle whereby the concrete may be mixed or transported or mixed during transportation.

The object of the invention generally is to provide a simplified and improved construction of machine whereby the materials of the concrete may be rapidly and thoroughly mixed. Among the particular objects of the invention is to provide improved means whereby water may be supplied to the mixer and diffused evenly through the dry materials with great promptness and the water conductor kept clear of clogging. Another object of the invention is to provide improved means for preventing the concrete materials from entering the discharge of the water supply pipe and means for protecting said preventing means. Other particular objects will appear from the disclosure herein.

The invention is embodied in the example herein shown and described, the features of novelty being finally claimed.

' In the accompanying drawing- Figure 1 is a view in side elevation of an apparatus according to the invention with a small portion broken out.

Fig. 2 is a rear view of the mixing vessel showing the closure for the discharge opening and its mounting.

Fig. 3 is mainly a central longitudinal section of the mixing vessel showing parts in full therein. Fig. 4 is a sectional detail of the water tank.

Fig. 5 is a sectional detail of one of the devices for protecting an outlet of the water supply conductor.

Fig. 6 is a similar section of another device for protecting another outlet of the water supply conductor.

In the views the truck is shown as an ordinary motor driven vehicle including the front and rear wheels and the chassis 10 supported thereby. The engine for propelling the vehicle is provided with the usual hood at 11 and the drivers cab shown at 12.

The mixing drum consists of a central cylindrical portion 13 having at its forward end a closed tapered portion 14 and at its rear a tapered portion 15 open at its terminus for the discharge of the mixed material. The dry materials are pref erably supplied through an opening in the cylindrical portion 13, said opening being covered with a removable but lockable closure 16.

The interior wall of the drum at its forward tapering portion 14 is provided with a series of substantially straight mixing blades 14- standing at right angles to the tangent of their direction of motion. The wall of the cylindrical portion of the drum is provided with spiral mixing and conveying blades 13 extended into the rear 5 tapering discharge portion as wider spiral blades 15.

The drum is preferably mounted horizontally on the chassis and to turn on its axis by means of rollers such as at 17 engaging a grooved track 10 18 fixed to and encircling the rear tapered end of the drum and by means of a standard 19 receiv-' ing a central hollow journal 20 at the axis of the forward tapered end of the drum.

Secured around the forward tapered end of the 15 drum is a toothed rack 22 engaged by pinion 23 on a shaft 24 adapted to be driven by a gasoline engine 25. The shaft 24 extends into a housing 26 containing a reversing gear mechanism operable by means of a handle 27 from the drivers 20 seat whereby the said shaft 24 can be driven first in one direction or the other, or not at all, when the power engaging means is in neutral position. Such a mechanism is shown in an application filed by Gebhard Jaeger, October 2,.1929, S. No.

The circular discharge opening at the rear end of the drum is surrounded by a projecting locking ring or flange 50.

The cover for the opening is designated 51. 30 The truck bed is equipped with a stationary frame for supporting the cover, said frame comprising converging slanting risers 52, and a top cross piece 53. The cover is movably supported in said stationary frame by means of a vertical standard 54 journaled at its lower end in a bearing 55 supported by the bracket 56 fastened to the truck bed, the upper end of the standard being journaled in the stationary frame. Said standard has a horizontal extension 5'7 from which pivotally depends a bent arm 58 to the lower end of which is fulcrumed a hand lever 59 having a sleeve 60 at its end loosely encircling the tubular extension of the cover. It will be observed that by this means the cover is capable of a sort of universal movement, that is, it can be swung bodily toward and from the discharge opening of the mixing drum on the axis of the vertical standard, upward and downward by struction and mode of operation of the cover are -'set forth in an application filed by me July 5, 1929, S. No. 376,108 which has matured into Fatthe journal 20 into the tank on the axis of the latter. The rear end of the said pipe 29 can,

if desired, be supported on a suitable spider 30,

flxed to the interior wall of the drum. Near its forward end the pipe 29 is made with a number of perforations 31 covered with a metallic sleeve 31' spaced from the pipe but secured to the pipe by a set screw 32 so that water can escape from the pipe into the drum. on the pipe beyond the forward end of the sleeve is secured a piece of flexible tube 32- of rubber normally closing the forward opening from the sleeve but adapted to be spread by pressure on the water to permit the discharge thereof into the mixing drum. This flexible sleeve is, in effect, a valve; and it is protected from injury by the materials being mixed by means of a metallic flaring shield 33 secured on the pipe forward of the flexible sleeve.

The pipe 29 is open at its rear end for the discharge of water into the mixing drum and said end is provided with a flaring metallic shield 34 secured to the end of the said pipe. 34 is carried a flexible disk 35 of rubber or leather, the rim of which normally bears against the inner wall of the shield, said disk acting as a valve adapted, when pressed by water in the pipe, to permit the escape of the water into the mixing vessel but to prevent the access of the mixed material in the vessel into the pipe. The metallic shield 34 protects the disk 35 from injury by the materials being mixed.

The water tank 28 has connected to its upper end the exhaust pipe 36 of the gasoline engine. In the lower end of said tank is a valve 37 to open and close the discharge of the tank to the pipe 29.

Said valve 37 has flxed to it a stem 38 extending upward through the tank and a small chamber 39 at the top' of the tank into which small chamber the exhaust pipe of the engine discharges. Loose on said stem 38- is a valve 40 adapted to close access of the exhaust pressure to the tank through the opening in the top of the tank, and on said stem 38 is a stop 41 adapted, when the valve 37 is lifted, to also lift the valve 40 thereby admitting exhaust pressure to the tank to expell water into the mixing drum.

The small chamber 39 has a vent at its upper end through which the stem 38 also extends; and loose on said stem is a valve 42 of a specific weight according to the maximum pressure it is desired to have exerted on the water in the tank. For example if it be desired that a maximum pressure of five pounds shall be exerted on the water in the tank said valve may be such as to weigh flve pounds, the excess escaping by popping said valve.

When it is desired that water shall be discharged into the mixing drum the driver raises the valve 37 by means of a bell crank lever 44, one arm of which is engaged internally with the rod 38 while the other arm is provided with handle 43 within reach of the drivers seat. By draw- In said shield ing the handle 43 downward both valves 37 and 40 are lifted thereby admitting engine exhaust pressure to the tank and the discharge of water into the mixing drum. Should the pressure in the tank begin to exceed the desired amount the valve 42 permits the discharge of the excess.

From the construction shown and described it will be apparent that by repeated liftings of the valves 37 and 40 the discharge of water can be accelerated anywhere in the line and that the movement of the water is not dependent on a head of water.

The materials to be mixed can be supplied to the drum preferably through the opening in the cylindrical portion thereof. But in the absence of such lateral opening or other such opening the drum can be charged through the discharge opening:

In practice the mixing drum of the construction as shown with the materials supplied thereto and the covers closed is rotated clock-wise, when viewed from the rear, to effect the mixing operation. The effect of such rotation is to move and mix while moving the materials forward toward and into the tapered end of the drum. Because the forward end is tapered its bottom being inclined and provided with substantially straight mixing blades the materials are returned to the cylindrical portion of the drum or counter to the-action of the spiral blades thereby causing a swirling or stirring as well as a cascading of the concrete materials.

The discharge of the mixed materials is preferably effected by remo'ving the cover of the end discharging opening and reversing the rotation of the mixing drum, that is, in the instance shown, by rotating it anti-clock-wise. But if desired or necessary the discharge can be effected through the lateral opening in the cylindrical portion of the mixing drum,.in which case the drum is turned and arrested to place the charging opening at the bottom and the materiaL-being fluent allowed to flow out by gravity.

The forms of the parts can be changed without departing from the gist of the invention as claimed. It will be understood, for example, that the exhaust from the engine for driving the vehicle can be used to produce the pressure.

This application is a division of an application flled by me December 7, 1929, Serial Number 412,529, patented Aug. 16, 1932, No. 1,872,624.

What I claim is:

1. In a concrete mixing apparatus, a mixing drum, a driving engine having an exhaust, a water tank discharging into the mixing drum, means connecting said exhaust with the water tank to create expelling pressure in the tank and means for limiting the amount of said pressure including a supplemental chamber having an outlet to the atmosphere, a valve for said supplemental chamber controlling the admission of pressure to the tank and a poppet valve for said outlet to the atmosphere.

2. In a concrete mixing apparatus, a mixing drum, a driving engine having an exhaust, a water tank discharging into the mixing drum, means connecting said exhaust with the water tank to create expelling pressure in the tank and means for limiting the amount of said pressure including a supplemental chamber having an outlet to the atmosphere, a valve for said supplemental chamber controlling the admission of pressure to the tank, a poppet valve for said outlet to the atmosphere and a rod in said tank for operating said controlling valve to admit pressure to the tank at will.

3. In a concrete mixing apparatus, a mixing drum, a driving engine having an exhaust, a water tank discharging into the mixing drum. means connecting said exhaust with the water tank to create expelling pressure in the tank and means for limiting the amount of said pressure including a. supplemental chamber having an outlet to the atmosphere, a valve for said supplemental chamber controlling the admission of pressure to the tank, a poppet valve of given weight for said outlet to the atmosphere and a rod in said tank for operating said controlling valve to admit pressure to the tank at will.

JOSEPH EGGERT. 

